sr20 bad maf??? DD please help =(

[c-los13]

motor is a sr20det s13 blactop on s13 hatch, stock everything. i parked the car about 2 weeks since i was selling some old parts and getting new ones. before i parked the car it ran great. good idle, good mpg. i finally turned on the car last night. it turned on fine but a few minutes later it started throwning black smoke running super rich and shaking. i unplugged the maf and the BLACK smoke and shaking WAS gone. since i dont have an extra sr20 maf i did some rewiring and installed a sohc maf. Installed the sohc maf and same shit, throws smokes when plugged, stops when unplugged. PLEASEEEEEEEEEEEEEEEEEEEEEEEEEEE HHHHELLLLLPPPP. ANY INPUT WOULD BE GOOD.....:smash:

[c-los13]

Come on somebodys gotta know!!!

[c-los13]

Bbbbbbbuuuuummmmmmmmmmmmmmmpppppppppp

[conrad_s13.5]

without being able to source a known good maf its hard to say.

have any friends / locals that could drive over and lone u theirs for the 5mins itd take to check?

when its plugged in and all,. where do your rpms drop?

[sharpe_corners]

I have a maf, 80 shipped 4 days to your door.

905 962 7498

[email protected]


Send me a text when your ready, I can ship out TODAY

[!Zar!]

Did you check for a leak in your intercooler pipes?

There is still a chance it could be a bad maf.

[c-los13]

Ima check the intercoller piping, also a mechanic said my air intake could have leak throwing off the readings. I hope I can get one of my friends to let me borrow his for a lil while. And to guy trynna sell me one, thanks and ill def let you know if I need it. Thanks a lot for the input everyone.

[JDMRIDDAZ]

coolant temp sensor..can do this
also a boost leak can do this

[Drft_S14]

Ive had the same problem, I changed my MAF and it went away

[c-los13]

Coolant temp sensor is fairly brand new. I got a friend stopping by today to let me borrow his maf. Ill update tonight.

[RB24_S14]

A bad ecu can do it too. Maybe moisture got on it or water drip down to the ecu. But the Maff could be it.

[c-los13]

Only thing in the back of my mind its the SOHC maf not working, I mean what are the odd ya know?? :/

[c-los13]

I forgot to mentioned that over the time I didn't drive the car it rained a lot and my windshield isn't sealed right. I thought about moisture too. Ima go home and open up the ecu to make sure is all dried as well. Would a bit of moisture ruin the ecu or can I fix it just by drying it up???? I can't wait to get outta work and do some test on the car

[c-los13]

Fml. I tried my friends maf (same motor). And the problem was still there. Decided to check out the ecu for any type of moisture and there it was! On one of the corners of the ecu there was some kinda dried up moisture where water may have landed. On the ecu connector and a small part on the pin out. I tried cleaning it up w an 'electrical cleaner' spray can. It looked good after the cleaning, I plugged it back in and same shit. FMFL. My ecu number is J4, I asked my friend to try out his ecu E5. The car would barely stay on. So now I can't tell if the ecu is bad or if maybe the water created a bad connection and burned out the wire that reads the maf since everything works fine unless the maf is plugged. I know this is long but I really need some help. A used J4 ecu is 250 bucks :(

[c-los13]

How can I check if the maf is getting any voltage??? I'm not sure if the ecu is bad or if the harness is.. Any input will be greatly appreciate

[c-los13]

I talked to one of guys at enthalphy (really nice ppl btw) he said to check voltage on the maf and on the ecu. I'm not experienced at all when it comes to wiring so I'm a bit confused. He said the 'black and white ' wire goin to the maf should read 12v. But what doesn't? Does it mean that the ecu is bad? Or maybe the ground for the maf got messed up?? I'm fucking clueless.

[JDMRIDDAZ]

Maf has 3 wires
12v
ground
ecu control wire...
TRY JDM OF MIAMI FOR ECU
LEGIT SELLER AND HAS EBAY STORE

[Darren]

Make sure your maf plug is not plugged in backwards...

also.. if there WAS a problem and you FIXED it, you may want to pull your plugs and make sure they're not still SOILED, and that's what's currently causing the problems.

Good luck with the fix

[c-los13]

My only concern is what if is not the ecu? What if its the harness? Will do dome work on the car later today. Thanks

[VNG704]

Theres a j4 on zilvia right now for $50 or so. Though I haven't read the actual fs thread. An e5 wont work on your car if you need a j4. I think the mafs wiring are the same, have him use your mafs.

[Darren]

My only concern is what if is not the ecu? What if its the harness? Will do dome work on the car later today. Thanks

You could look into Wiring Specialties, they are reasonable and have a great product, they also have a harness repair service

[Kingtal0n]

What if the maf sensor is good but it is reading airflow that is not entering the engine?

I would do a boost leak check before buying any parts.

[c-los13]

I checked the plugs today and they were hella black. That explains why my friends maf didn't work. I put some old spark plugs and the car actually stayed on for a lil while without smoking. I tried revving in and it started smoking. I'm gonna buy new plug and try my friend maf again. Wish me luck. I got quote 300 from wiring specialist for a new harness to fit redtop ecus, just in case my ecu is fried. Gonna take off bumber and get a compressor to do a boost leak test as well. Damn I miss my car. I had just gotten stance coilovers and new wheels and this shit happened. Bummer from hell.

[c-los13]

Update: i got new spark plugs andrewired the single cam maf. Turned on car and let it idle for a while. No smoke til now. As soon as i revved it the black smoke started coming out again. I turned off the car right away cuz i didnt wann messed up my spark plugs again. So Pparently itsnot the maf :( help.

[reallygood101]

got the same problem wit my s14 sr20, i still havent found out wat it was and i put in new plugs, wrking maf, new tps, way better BOV, checked for leaks and still the same shit, i just got a wrking ecu in yesterday so im gonna b throwing that in and hopfully it wrks

[c-los13]

Sorry to hear that, i got better bov too (synapse), lmk if a new ecu fixes your problem since thats what im trying next. Thanks

[reallygood101]

update brotha, i put in the ecu i just got and the car is idling WAY better, no blck smoke and doesnt shake anymore and no breaks or back firing when reving it, so i would say get a new ecu... oh and also i replaced the IACV

[c-los13]

Alright. Yeah my iacv had calcium builup when i got the motor but i got it pretty cleaned up. I guess its time for a new ecu. I will update soon. Where did you get a new iacv?

[reallygood101]

i buy 95% of the stuff for my 240sx off the FS section so take some time and check it out you should find one fairly quick

[c-los13]

Update. Nobody around here had a j4 ecu so i ended up buying a brand new harness from wiring specialist ( yuri is great btw), and getting a redtop ecu from a friend. I installed evevything and turned on the car. It idled perfect for a lil whie and then it started again the damn black smoke again. I turned off the car because i didnt wanna ruin my brand new spark plugs (3rd ones). i also put a fuel gauge and the pressure its a 38 at idle. Wtf is going on? Im about to give up. When i took off one of the plugs i could see a bit of black smokecoming out still. What could it be? I pull the codes from the ecu and it gave me 55. Help please. I need my car really bad

[starplatnumm]

i had a similar problem on the s14 Sr. changed the fuel pump. changed the MAF. made sure that all sensors are connected as well. it turns out that the MAF pig tail had a little tension. harness could have been broken. but since the S14 SR MAF are not interchangeable due to the part numbers. i notice the wires by the MAF plug were exposed. i disconnect the MAF and it ran and idle perfect. but putting the MAF on it ran like shit. so i had my brother fixed the pigtail and cover the exposed area due to tension. it ran like if were brand new. but you have to make sure that all harness plugs were connected properly. and yes people with the S14 SR you must buy another MAF with the same part number as the existing one. unless you tune your ECU for the Z32 MAF.

[c-los13]

As i mentioned i got a brand new harness from wiring specislist. Weird thing i just noticed...after i let car idlenfor a lil bit, i removed the soark plugs to check and the 4th cylinder still throwing a lil bit of smoke...

[anarchyperf]

I'll put money on 02 sensor. The SR ecu will run closed loop until it warms up and then switch to open loop reading from the sensor. When it starts acting up unplug the 02 and see if it idles any better

[c-los13]

I did that when the problem started and it didnt make a difference. The only time the smokes stops is when i unplugged the maf. But then again i tried a perfect running maf and same shit. Im seriously lost.

[c-los13]

Im starting to think that its the bov..i bought a brand new synapse from frsport. Its not recicurlating. Couldnthat be the problem. Also when i push on inside the bov it goes in pretty easy. I remember my hks was hella hard. Maybe this is creating a major boostleak. Right?

[c-los13]

Its the damn bov! I doesnt hold any air when the car is on creating a major boost leak im calling frsport tomorrow. I tried setting it up diferent ways and it was the same. Damn synapse. I really thought they were the best. Btw im selling my j4 harness w ecu since its good after alll. :wiggle:

[92SEric240sx]

was it the bov itself or the seal on the pipe flange?

[c-los13]

It was the bov itself, synapse bov are meant for motor that use a map sensor instead of a maf like in sr20s. I recirculated the bov back to the intake and it fixed the problem. For future reference anyone having this type of issues should check if their bov stays open or its leaking. Btw if anyone doesnt recirculate they can just buy the anti stall kit from synapse.

[RHSIL80]

if your spark plugs are black and wet it could be injectors or even just the injector o_rings, I pinched my Injector o-rings once a d had this problem